CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Revenues and other income:
Oil and gas revenue	$ 193,413	$ 112,214	$ 421,479	$ 227,985
Interest income	44	282	114	1,028
Other income	321	175	575	205
Total revenues and other income	193,778	112,671	422,168	229,218
Costs and expenses:
Oil and gas production	22,674	19,592	47,075	26,918
Exploration expenses	93,050	16,901	116,346	56,545
General and administrative	43,111	34,799	83,141	74,122
Depletion and depreciation	58,562	32,999	117,211	64,648
Amortization-deferred financing costs	2,785	2,194	5,483	4,388
Interest expense	10,017	10,446	19,008	23,504
Derivatives, net	(12,707)	(1,982)	(7,199)	1,878
Other expenses, net	849	44	1,481	792
Total costs and expenses	218,341	114,993	382,546	252,795
Income (loss) before income taxes	(24,563)	(2,322)	39,622	(23,577)
Income tax expense	46,253	22,521	90,344	38,807
Net loss	$ (70,816)	$ (24,843)	$ (50,722)	$ (62,384)
Net loss per share:
Basic (in dollars per share)	$ (0.19)	$ (0.07)	$ (0.13)	$ (0.17)
Diluted (in dollars per share)	$ (0.19)	$ (0.07)	$ (0.13)	$ (0.17)
Weighted average number of shares used to compute net loss per share:
Basic (in shares)	376,563	370,720	375,927	369,973
Diluted (in shares)	376,563	370,720	375,927	369,973